Je

Jenner, Edward
Credited as the pioneer of smallpox vaccine, and is sometimes referred to as the "Father of Immunology"; his works have been said to have "saved more lives than the work of any other man".
Jerk
A vector quantity that specifies time rate of change of acceleration.
Jerk Pump
A fuel pump which injects fuel into the cylinder by action of a cam having a sharp nose.
Jeroboam
The name of a wine bottle equivalent to the volume of 4 standard bottles or 3 litres.
Jet Assisted Takeoff
Utilising solid or liquid fuel rockets to augment the take-off power of an aircraft′s engines.
Jet Engine
An engine that discharges a fast moving jet of fluid.
Jewellers Screwdriver
A small precision screwdriver.